Rulon^® 123 “Shoes” Vanquish Elevator Door Rattles

Elevator manufacturers have always had to contend with the rattles that occur in elevator doors as they traverse the daily ups and downs. A major manufacturer, known for some of the longest rides in high end properties, contacted TriStar to find a solution that would improve upon the rattle-mitigation methods traditionally employed.

Why Traditional Solutions Fell Short

To reduce door rattles, manufacturers typically use over-molded nylon shoes on stamped steel plates, bolted to the bottom of doors to ride in floor tracks. However, these solutions aim to reduce—not eliminate—the problem. Frequent motion, impact, vibration, and moisture—whether from humidity or the wet clothing of riders—take a toll on the nylon material over time. Swelling of nylon can lead to possible stiction in the guide track and squeaking, and the constant wet/dry cycles eventually lead to a breakdown of physical properties.

Rulon 123: A Durable, Rattle-Free Solution

After consulting with the manufacturer, our engineers developed a solution that offered greater stability, minimal stiction, self-lubrication, and improved conformity to the tracks. We retained the current nylon over-mold to a steel bracket concept but replaced the nylon with Rulon 123. This grade of Rulon is one of the lowest friction materials available at TriStar. It is available in a bondable tape form, is very conformable, and cost efficient.

To eliminate nylon entirely, our engineers replaced it with a rubber core over-molded onto the bracket. They then bonded Rulon 123 tape around the rubber for added performance. The shoe was designed to fit with minimal clearance on either side, but the compressibility of the rubber and low friction “silent” Rulon tape proved to be a winning combination. This not only eliminated the rattle potential, but it also made for a very smooth and quiet door movement, yielding years of maintenance free performance.

Creative Solutions and Solid Engineering are Always a Winning Combo

TriStar's deep expertise in polymer materials provided an elegant, simple, and cost-effective solution to the manufacturer’s challenge. If you have an application that requires a fresh approach and extensive materials knowledge, TriStar engineers are here to help.